Biremis circumtexta

(Meister ex Hustedt) Lange-Bertalot & Witkowski in Witkowski, Lange-Bertalot & Metzeltin 2000      Category: Symmetrical biraphid
BASIONYM: Navicula circumtexta Meister ex Hustedt in A. Schmidt et al. 1934

Bacillaria paradoxa


Boreozonacola hustedtii

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - October 2011
Length Range: 26-36 µm
Width Range: 6.0-7.1 µm
Striae in 10 µm: 16-18


Valves are lanceolate with slightly protracted apices. Raphe is straight with proximal ends slightly expanded and deflected to the primary side. Striae are marginal, forming a wide, lanceolate axial area. Each marginal stria consists of four areolae, which are easily observed under LM. There is also a longitudinal row of areolae adjacent to the raphe slits on the primary side of the valve. Externally, a thin conopeum extends from the valve margin and covers the areolae, except those those areolae adjacent to the axial area. The conopeum can be observed only under SEM, but under LM, its margin is visible as a longitudinal line crossing the striae. The striae are slightly radiate in the valve center, becoming parallel near the apices.

Original Description

Basionym: Navicula circumtexta
Author: Meister ex Hustedt in A. Schmidt et al. 1934
Length Range: µm
Striae in 10 µm:

Original Description

Kiang Wau, Ostasien. Navicula circumtexta Meister, nov. spec. Die mittlere, von den Längslinien eingefaβte Schalenpartie lieft höher als die Randzone.

Original Images

Cite This Page:
Potapova, M. (2011). Biremis circumtexta . In Diatoms of the United States. Retrieved August 26, 2016, from

Species: Biremis circumtexta

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Schmidt, A. (-). (1874-1959). Atlas der Diatomaceen-Kunde, von Adolf Schmidt, continued by Martin Schmidt, Friedrich Fricke, Heinrich Heiden, Otto Muller, Friedrich Hustedt. Reprint 1984, Koeltz Scientific Books, Konigstein, 480 plates.

Witkowski, A., Lange-Bertalot, H. and Metzeltin, D. (2000). Diatom Flora of Marine Coasts I. Iconographia Diatomologica 7: 1-925.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Biremis circumtexta CAS

North American Diatom Ecological Database (NADED)

NADED ID: 206001

Autecology Discussion

Biremis corcumtexta is usually found in inland waters of high mineral content or in coastal habitats